1. Field of the Invention
The present invention relates to a water-resistant camera, and more particularly to a water-resistant camera for taking pictures underwater or in humid environments, the camera having a lens barrel or mount movable toward and away from the fluid-tight camera body.
2. Description of the Prior Art
Some cameras have lens barrels or mounts movable toward and away from the camera bodies. Movable lens barrels or mounts are designed to vary the distance between the foremost lens (or the front glass panel in front of the foremost lens) and the focal plane in the camera body over a relatively large range in order to switch between telephoto and wide-angle modes, to effect zooming, or to move a collapsible lens assembly toward and away from the camera body.
The camera body of a water-resistant camera for underwater or beach use is normally fluid-tight when close, and it cannot allow for air pressure variations therein. Therefore, it would be impracticable to incorporate movable lens barrels in water-resistant cameras, because back-and-forth movement of the lens barrel would change the volume of the entire camera body including the lens barrel, thus varying the air pressure in the camera. Another known water-resistant camera type has an electronic flash selectively movable into a projected position out of the camera body for use and into a retracted position in the camera body for storage. Movement of the electronic flash into and out of the camera body would also cause variations in the air pressure in the camera body.
Consequently, water-resistant cameras with movable lens barrels and/or electronic flashes are not of a fluid-tight structure in a strict sense. For taking pictures with such a camera having a movable lens barrel and/or electronic flash, it has been customary to place the camera in a transparent water-resistant case, and to operate the camera from outside of the case when it is used underwater or in a humid environment. This practice is however quite awkward because the camera is not handled directly by the user.